The invention relates to a process for the continuous catalytic hydrogenation of materials which can be hydrogenated in a flowable form, i.e., materials which are liquid or in a paste-like form. Preferably the process is carried out at elevated temperature and under pressure.
The basic chemistry and technology of hydrogenation processes are well-known. Suitable materials and apparatus are available for hydrogenation, and an extraordinarily large number of catalysts and catalyst systems are known directed to particular hydrogenation reactions. One disadvantage of prior art hydrogenation processes and of prior art hydrogenation catalysts is that the catalysts which are most effective for use are generally also the most costly catalysts. For example, the elements from Group VIII of the Mendeleev periodic table, i.e., platinum, palladium, iridium, etc., are excellent catalysts, but they are also extremely expensive. Platinum is particularly advantageous in hydrogenation reactions since it usually proceeds more quickly and/or at lower temperatures with respect to other catalysts. Nevertheless, in general practice platinum is not used due to its high cost. Instead, a less active but less costly catalyst is selected which is a compromise between hydrogenation activity and economy of catalyst. A known area of endeavor, therefore, is the finding of a process which achieves an increase in hydrogenation efficiency with a given catalyst or catalyst system.